Pump assembly with one piece piston

ABSTRACT

An assembly including a pump attachment particularly adapted to form an nonaerosol pump sprayer, and a method of using the same. The apparatus desirably includes an attachment having a pump sprayer which is pressurized on the upstroke enabling the sprayer to be shipped and stored in a relaxed position. The attachment includes a body, a coupling, a shaft, a piston, an inlet valve and a biasing member. The body defines an elongate chamber having the first end, second end, and an interior wall extending between the first end and second end. The coupler is sized and shaped to secure the body to the neck of a container. The shaft extends through the opening in the first end of the chamber and defines an internal flow channel. The piston is reciprocally mounted within the chamber and includes an inner annular surface surrounding the shaft and an outer annular surface sized and shaped to form a sealing engagement with the interior wall of the body. The attachment defines a sealing surface substantially fixed with respect to the piston and a second sealing surface substantially fixed with respect to the shaft. The first sealing surface and the second sealing surface having the first position wherein the first sealing surface and the second sealing surface cooperate to prevent the flow of liquid between the piston and the shaft. The first sealing surface and the second sealing surface also has a second position wherein the first sealing surface and the second sealing surface permit the flow of liquid between the piston and the shaft. The piston is formed from a single piece said piston and defines an inner annular surface surrounding the shaft and an upper outer annular surface sized and shaped to form a sealing engagement with said interior wall of the body and a lower outer annular surface sized and shaped to form a sealing engagement with the interior wall of said body.

RELATED APPLICATIONS

This application is a continuation of 08/949,837 filed Oct. 14, 1997,U.S. Pat. No. 6,089,414 which is a continuation-in-part of U.S. patentapplication Ser. No. 08/812,790, filed Mar. 6, 1997 now U.S. Pat. No.5,816,447.

FIELD OF THE INVENTION

This invention relates to pumps and, in particular, to nonaerosol pumpsprayers.

BACKGROUND AND SUMMARY OF THE INVENTION

Noncontainer pressurizing pump sprayers commonly utilize an integralcylinder and plunger arrangement to generate pressure to expel liquid,such as insecticide and fertilizer from a container. Noncontainerpressurizing pump sprayers are desirable in that they do not utilizepressurized containers which must be handled carefully and at controlledtemperatures to avoid the risk of explosion. Noncontainer pressurizingpump sprayers have a number of other advantages, including not usingpropellants which destroy the ozone and being relatively inexpensive.

There are two common varieties of noncontainer pressurizing pumpsprayers: pump sprayers that are pressurized on the upstroke and pumpsprayers that are pressurized on the downstroke. Pump sprayers that arepressurized on the downstroke typically utilize a return spring whichbiases the plunger upward after the pressurization stroke. Thesesprayers suffer from the drawback that it is often undesirable to storeor ship the pump sprayer with the plunger in the up position.Accordingly, the pump sprayer is generally shipped and stored with thereturn spring in a compressed position, causing the spring to fatigueand begin to wear out prematurely. Likewise, in the event of theinadvertent release of the return spring, the plunger cannot bedepressed without pressurizing the fluid in the container. In the caseof insecticide or other toxic chemicals, this is often undesirable.

While pump sprayers that are pressurized by pulling the plunger upwardhave the advantage of not having the plunger being forced outwardinadvertently, they too, suffer from a number of drawbacks. For example,once the plunger is drawn upward, it is generally not possible to lowerthe plunger without discharging fluid. As drawing the plunger upwardcreates a relatively large volume of pressurized liquid, this eitherrequires that a relatively large amount of fluid be wasted or the devicebe stored with the plunger extending outward.

U.S. Pat. No. 4,174,055, to Capra, et al., discloses an alternativedispenser. The disclosed dispenser incorporates a plunger whichpressurizes the fluid on the upstroke, but also is provided with aseparate return spring and collar for purposes of lowering the plungerhandle independently of the main plunger piston. While this arrangementhas advantages, it is more complicated and expensive than other pumpsprayer arrangements. Further, while the system provides for slowbleeding off of pressure, the sprayer remains in a pressurized state forsome time. Significantly, this substantially increases the risk ofinadvertent discharge of chemicals by adults or children who may comeinto contact with the device.

The present invention includes an apparatus and pump attachmentparticularly adapted to form a noncontainer pressurizing pump sprayerwhich overcomes the drawbacks of the prior art. The apparatus desirablyincludes an attachment having a pump sprayer which is pressurized on theupstroke, enabling the sprayer to be shipped and stored in a relaxedposition. Importantly, however, the plunger is adapted to permit theplunger to be quickly and easily lowered and the apparatus depressurizedwithout discharging fluid. Significantly, these advantages are providedin a apparatus which is particularly adapted to be inexpensivelymanufactured and includes few moving parts, to enhance reliability.

One aspect of the invention is a pump attachment for a containerdefining a neck including a body, a coupling, a shaft, a piston, aninlet valve and a biasing member. The body defines an elongate chamberhaving a first end, a second end, and an interior wall extending betweenthe first end and the second end. The coupler is sized and shaped tosecure the body to the neck of a container. The shaft extends throughthe opening in the first end of the chamber and defines an internal flowchannel. The piston is reciprocally mounted within the chamber anddefines an inner annular surface surrounding the shaft and an outerannular surface sized and shaped to form a sealing engagement with theinterior wall of the body. The piston separates the chamber into anupper portion above the piston and lower portion below the piston. Theinlet valve is at the second end of the body and is configured to permitthe flow of fluid into the chamber and restrict the flow of fluid out ofthe chamber. The biasing member is positioned between the piston and thefirst end of the chamber.

The attachment defines a first sealing surface substantially fixed withrespect to the piston and a second sealing surface substantially fixedwith respect to the shaft. The first sealing surface and the secondsealing surface have a first position wherein the first sealing surfaceand the second sealing surface cooperate to prevent the flow of liquidbetween the piston and the shaft. The first sealing surface and thesecond sealing surface have a second position wherein the first sealingsurface and the second sealing surface permit the flow of liquid betweenthe piston and the shaft.

Advantageously, the shaft includes an outwardly extending surface whichprevents the piston from sliding beyond the one end of the shaft.Likewise, the attachment desirably includes a first O-ring mounted onthe shaft which defines the second sealing surface and an inwardlytapered seat which defines the first sealing surface. Alternatively, thepiston may comprise one piece and define an upper outer annular surfacesized and shaped to form a sealing engagement with the interior wall ofthe body and a lower outer annular surface sized and shaped to form asealing engagement with the interior wall of the body. Desirably, theupper outer annular surface is defined by an upper lip adapted to flexoutward in response to downward pressure and the lower outer annularsurface is defined by a lower lip adapted to flex outward in response toupward pressure.

The attachment may also include a spray nozzle communicating with theinternal flow channel and an actuator for selectively preventing theflow of a fluid through the spray nozzle.

The attachment desirably includes a handle secured to the shaft and alatch movable between a first location wherein the latch generallyprevents the shaft from being drawn through the first end of the bodyand the second location wherein the latch generally permits the shaft tobe drawn through the first end of the body. Alternatively, the handle isintegrally formed with the shaft so as to form a single piece plunger,thereby eliminating a potential leak point.

Another aspect of the invention is an apparatus including a containerdefining a neck and an attachment. The attachment includes a body, acoupler, a shaft, a piston, an inlet valve, and a biasing member. Thebody defines an elongate chamber having a first end, a second end and aninterior wall extending between the first end and the second end. Thecoupler is sized and shaped to secure the body to the neck of thecontainer. The shaft extends through an opening in the first end of thechamber and defines an internal flow channel. The piston is reciprocallymounted within the chamber and defines an inner annular surfacesurrounding the shaft and an outer annular surface sized and shaped toform a sealing engagement with the interior wall of the body. The pistonseparates the chamber into an upper portion above the piston and a lowerportion below the piston. The inlet valve at the second end of the bodyis configured to permit the flow of fluid into the chamber and restrictthe flow of fluid out of the chamber. The biasing member is positionedbetween the piston and the first end of the chamber.

The attachment includes a first sealing surface substantially fixed withrespect to the piston and a second sealing surface substantially fixedwith respect to the shaft. The first sealing surface and the secondsealing surface have a first position wherein the first sealing surfaceand the second sealing surface cooperate to prevent the flow of liquidbetween the piston and the shaft. The first sealing surface and thesecond sealing surface have a second position wherein the first sealingsurface and the second sealing surface permit the flow of liquid betweenthe piston and the shaft.

Another aspect of the invention is a method of arming and disarming aspray apparatus, including a container containing fluid and anattachment mounted thereto having a body defining an elongate chamber, ashaft extending through an opening in the chamber, the shaft defining aninternal flow channel, a piston reciprocating mounted in the chamber, acheck valve and a biasing member, including (1) moving the shaft in afirst direction relative to the body, thereby moving the piston in thedirection and drawing fluid from the container into the chamber throughthe check valve and compressing the biasing member; (2) permitting thebiasing member to force the piston against the fluid in the chamber in asecond direction pressurizing the fluid; (3) releasing liquid from thechamber through the internal flow channel in the shaft; and (4) movingthe shaft in a second direction relative to the body and the piston torelease a seal between the piston and the shaft; thereby permitting theflow of fluid between the piston and the shaft depressurizing the fluid.

Another aspect of the invention is a spray nozzle including a grip, anose having a spray end, a valve housing, a valve and an actuator. Theactuator is connected to the valve. The valve housing is mounted withineither the grip or the nose. The valve housing defines a closed end, aninlet port and an outlet port. The valve is mounted within the housingand has a flow portion, a first seal on one side of the flow portion andthe second seal on the other side of the flow portion. The valve has afirst position wherein the valve prevents the flow of fluid between theinlet port and the outlet port, and a second position wherein the valvepermits the flow of fluid between the inlet port and the outlet port.The first seal and the second seal are positioned to one side of theinlet port when the valve is in the first position. The first seal andthe second seal are positioned on opposite sides of the inlet port andthe outlet port when the valve is in the second position. Desirably, thevalve comprises a one-piece shaft member and no more than two O-rings.

Yet another aspect of the invention is an assembly for a container. Theassembly includes a grip, a coupler sized and shaped to secure the gripto the neck of a container, a plug and an adaptor. The grip includes ahandle portion and a stem portion. The handle portion has a first innerwall defining a first flow channel having a first outlet. The stemportion defines a second inner wall defining a second flow channelhaving a second outlet. The first flow channel and the second flowchannel intersect at the outlet of the second flow channel. The plug ismounted within the first flow channel and has a first position whereinthe plug prevents fluid flow from the second outlet to the first outlet,and a second position wherein the plug permits fluid flow from thesecond outlet to the first outlet. The adaptor has an inner sectionsized and shaped to be inserted into the first flow channel to move theplug between the first position and the second position. Desirably, theplug further includes an inner flow channel through which fluid isflowable when the plug is in the second position. The adaptor preferablycomprises a connector for securing a piece of tubing to the handleportion of the grip.

Finally, yet another aspect of the invention is an assembly including acontainer and a sprayer. The container defines a wall, a first stud anda second stud. Each of the first stud and the second stud include a headportion and a stem portion. The sprayer has a spray end and a wall. Thewall defines a first opening and a second opening. Each of the openingsincludes a first portion wider than the stem portion and narrower thanthe head portion, and a second portion wider than the head portion sothat the head portion of the stud is insertable therethrough.Advantageously, the container includes a seam and the first stud and thesecond stud intersect the seam. Preferably, the second portion of theopening is positioned closer to the spray end than the first portion ofthe opening. Desirably, for each of the first stud and second stud, thehead portion overhangs the stem portion a first overhang distance on afirst side, and a second overhang distance on a second side. At leastone of the first overhang distance and the second overhang distance isadvantageously at least 0.015 of an inch.

BRIEF DESCRIPTION OF THE DRAWINGS

These and other aspects of the invention will now be discussed inconnection with the accompanying drawings, which form a part hereof.

FIG. 1 is a vertical sectional view of an apparatus including a pumpattachment, in accordance with a preferred embodiment of the invention,showing the parts in their normal at-rest position.

FIG. 1a is an enlarged sectional view of the area with the circle 1 a—1a of FIG. 1.

FIG. 1b is an enlarged sectional view of the area within the circle 1b—1 b of FIG. 1a, illustrating an open vent passage.

FIG. 1c is an enlarged sectional view similar to FIG. 1b, butillustrating a closed passage.

FIG. 1d is an enlarged sectional view similar to FIG. 1a, but showingthe handle plug used during shipping.

FIG. 1e is an enlarged view of a locking ring used by the adaptor.

FIG. 2 is a vertical sectional view of the device of FIG. 1, showing theactuator moved to an upwardly or outwardly telescoped position relativethe container in order to move the piston in the accumulating chamber orreservoir to compress the biasing member and pressurize fluid within thechamber.

FIG. 3 is a sectional view taken along 3—3 of FIG. 2, illustrating thelatch in an unlocked position.

FIG. 4 is a sectional view similar to FIG. 3, but illustrating the latchin a locked position.

FIG. 5 is a partial sectional view illustrating the pump attachment in afully pressurized position.

FIG. 6 is a partial sectional view illustrating the release of pressurein the chamber by means of an external downward force on the handle.

FIG. 6a is an enlarged sectional view of the area 6 a —6 a of FIG. 6illustrating the flow of fluid between the outer surface of the shaftand the inner annular surface of the piston.

FIG. 7 illustrates the pump attachment in its fully locked and retractedposition quickly depressurizing through the flow of fluid between theshaft and the piston.

FIG. 8 is a view similar to FIG. 6a illustrating a first alternativepiston design.

FIG. 9 is an enlarged sectional view of a second alternative pistondesign.

FIG. 9a is a top plan view of the piston of FIG. 9.

FIG. 9b is a bottom plan view of the piston of FIG. 10.

FIG. 10 is an enlarged sectional view of a third alternative pistondesign.

FIG. 11 is a sectional view of an alternative handle and shaft design,where the handle and shaft are integrally formed.

FIG. 12 is a perspective view of a prior art container and sprayerassembly.

FIG. 13 is an enlarged view of the sprayer of the assembly of FIG. 12.

FIG. 14 is a sectional view illustrating the connection between thesprayer and container of FIG. 12, when the sprayer is mounted on thecontainer.

FIG. 15 is a front elevational view of a preferred apparatus including acutout illustrating the manner in which the sprayer is mounted on thecontainer.

FIG. 16 is a left side view of the container of FIG. 16, without thespray attachment mounted thereon.

FIG. 17 is an enlarged schematic sectional view illustrating the methodof molding the container of FIG. 15, including a bayonet attachment.

FIG. 18 is a top plan view of an alternative sprayer.

FIG. 19 is a front elevational view of the sprayer of FIG. 18.

FIG. 20 is a sectional view of the sprayer of FIG. 18 taken along 20—20.

FIG. 21 is a sectional view of the sprayer of FIG. 19 taken along 21—21.

FIG. 22 is an enlarged partial sectional view of the valve mechanism ofa sprayer in a closed position.

FIG. 23 is a partial sectional view of the valve mechanism in an openposition.

FIG. 24 is a partial sectional view of an alternative valve mechanism ina closed position.

FIG. 25 is an enlarged partial sectional view of the sprayer of FIG. 24in an open position.

FIG. 25a is an enlarged sectional view along 25 a —25 a of FIG. 25.

FIG. 26 is an enlarged partial sectional view illustrating a secondalternative embodiment of the valve mechanism of a sprayer in a closedposition.

FIG. 27 is a partial sectional view of the valve of FIG. 26 in an openposition.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

Referring now to FIG. 1, an assembly 10 will now be described. Theassembly 10 includes a container 20 and pump attachment 30. Thecontainer 20 is illustrated partially filled with fluid 260. Thecontainer 20 defines an internal space or reservoir 22 and a neck 24which defines an opening or port 26. The neck 24 desirably defines aseries of external threads 28.

The attachment 30 includes a body 40, which is secured on the container20 by means of a coupler 70. The attachment further includes a shaft 110which is connected to a piston 130. A handle 190 is mounted on the shaft110. A wand or spray nozzle 220 is connected to the handle 190 by tubing222. Advantageously, the nozzle 220 includes a release valve, whichcontrols the flow of fluid through the spray nozzle 220 and an actuator240 for controlling the release valve.

Referring to FIG. 5, the body 40 of the attachment 30 will now bedescribed in detail. The body 40 defines an internal chamber 42. Thebody 40 includes first or upper end 44, a second or lower end 46 and acylindrical internal wall 48. The upper end 44 of the body 40 includesan outwardly tapering portion 50 and an upper cylindrical flange 52,provided with internal threads 54. The lower end 46 of the body 40 isprovided with an annular overhanging lip 56 defining a series ofopenings 58 and a depending flange 60 extending downward from theannular lip 56 surrounding the opening 58.

Referring to FIGS. 3-4 and 5, the coupler 70 includes a disk-shaped base72 which partially defines a central aperture 74. A coupler 70 includesa pair of depending and concentric annular lips. The first or innerannular lip 76 likewise partially defines the aperture 74. The second orouter annular lip 78 is spaced from and surrounds the inner annular lip76.

The inner annular lip 76 defines an overhanging flange 82 and adepending ridge 84. The inner lip 76 and the overhanging flange 82cooperate to define a handle seat. The overhanging flange 82 anddepending ridge 84 cooperate to define an inner O-ring seat. The firstannular lip 76 and the depending ridge 84 likewise form an outer annularspring groove 88. The inner annular lip 76, the base 72 and outerannular lip 78 cooperate to define a first annular channel 90. Whichdefines a seat which receives an O-ring 91. The outer annular lip 78 isprovided with internal threads 96.

Alternatively, the flange 52 of the body 40 could be provided withexternal threads and the lip 76 of the coupler 70 with internal threads.This arrangement would facilitate tooling to form the body.

The shaft 110 has a first or upper end 112 and a second or lower end114. The upper end is provided with external threads 116. The lower end114 of the shaft 110 advantageously includes a radially outwardextending portion 118. The shaft includes an internal wall 120 whichdefines an internal flow channel 122 having a lower inlet end 124 and anupper outlet end 126.

Referring to FIGS. 6 and 6a, the piston 130 is mounted around the shaft110. The piston includes a body 132 having a top 134 and bottom 136. Thepiston defines an inner annular surface 138, which defines an internalchannel 140. The inner annular surface 138 desirably defines a taperingportion 142. The piston 130 desirably additionally includes a series ofradially extending locating ribs which define a series of upper surfaces144. These surfaces 144 cooperate to define an outer annular groove 146for receiving the biasing member 180.

Referring to FIGS. 5 and 6, the piston 130 divides the internal chamber42 of the body 40 of the attachment into a first or upper portion 150and a second or lower portion 152. Mounted within the opening 58 definedby the overhanging lip 56 of the lower end 46 of the body 40 is theinlet or check valve 160. The check valve 160 permits the flow of fluidinto the internal chamber 42 of the body 40 of the attachment, whilepreventing the flow of fluid out of the internal chamber 42.Advantageously, the check valve 160 is provided with an upper nipple 162which mates with the inlet 124 of the shaft. The lower nipple 166secures the check valve 160 in place. Likewise, the check valve isprovided with a lower nipple 166 depending from the overhanging lip 56of the lower end 46 of the body 40. The check valve defines a centralflow channel 168.

The biasing member 180 has a first or upper end 182 which is seated inthe outer annular spring groove 88 of the coupler and a second end 184which is seated in the annular groove 146 in the top of 134 of thepiston 130.

Referring to FIG. 5, the handle 190 is mounted on the upper end 112 ofthe shaft 110. The handle includes a vertical stem 192 and a grip orhorizontal portion 194. The horizontal portion is desirably integrallyformed with an upper end 196 of the stem 192 and the lower end 198 ofthe stem 192 is desirably secured to the upper end 112 of the shaft 110.The stem desirably defines an internal flow channel 200. The lower end198 of the stem 192 desirably defines a larger mouth portion 202 whichdefines internal threads 204 with the external threads of 116 on theupper end 112 of the shaft 110. The horizontal portion 194 desirablylikewise defines an internal flow channel 206 which communicates withthe internal flow channel 200 of the stem 192, and includes a closed end208 and an open end 210.

Referring to FIGS. 1 and 1a-1 d, the attachment of the tubing 222 to thehorizontal portion 194 of the handle 190 will now be described. Toensure a fluid-tight seal, the tubing 222 is locked to a connector or300 and the adaptor 300 is locked to the horizontal portion 194 of thehandle 190. As seen in FIG. 1a, the adaptor 300 has a disc-shaped outersection 302, a cylindrical intermediate section 304 and a smallerdiameter cylindrical inner section 306. A cylindrical wall 307 definesan interior flow channel 309 running the length of the adaptor. Theintermediate section 304 includes an enlarged annular stop 308 proximateto the inner section 306. The inner section 306 includes an annularlocking flange 310 which mates with a corresponding annular detent inthe horizontal portion 194 of the handle 190. The inner section 306further comprises a first sealing ring 312 and a second sealing ring 314spaced inward from the locking flange and sized to form a fluid-tightseal with the wall defining the internal flow channel 206 of thehorizontal portion 194 of the handle 190. The outer section 302 definesa pocket 316 for receiving a locking ring 318. As best seen in FIG. 1e,the locking ring 318 defines a plurality of gripping edges or corners320, which are adapted to apply pressure against the outer surface ofthe tubing 222 and prevent it from being inadvertently pulled from theadaptor 300.

FIG. 11 shows an integrally formed one-piece handle and shaft or plunger424 which may be used in place of the two-piece handle and shaftdescribed above. The integral plunger 424 would eliminate a possibleleak point between the handle and shaft. The plunger 424 includes ashaft portion 426 and a handle portion 428 which are joined at a stopcollar 430. The handle portion 428 includes as vertical stem section 432and a horizontal grip section 434. The shaft portion 426 of the plunger424 includes an internal wall 436, which mates with a plug 438. The plugincludes an insert portion 440 which is received within the shaftportion 426 and an exterior portion 442 which protrudes outside of theshaft portion 426. The insert portion 440 includes a radially extendingannular ridge 444 which mates with an annular recess 446 in the internalwall 436 of the shaft portion 426.

Alternatively, it may be desirable to provide external threads on thedistal end of the shaft portion 426 and an alternative plug withinternal threads to mate therewith would eliminate the need for theannular recess 446 in the inner surface of the shaft which couldfacilitate the molding of the plunger 424.

Illustrated in FIG. 11a is an alternative adaptor or connector 850secured within the handle portion 428 of the one piece plunger 424. Theconnector 850 has a larger diameter head portion and a smaller diameterbody portion. Importantly, the connector 850 avoids the use of a lockingring. The elimination of the locking ring facilitates the quick and easyattachment of the connector 850 to the plunger 424, while an addedO-ring 852 adjacent to the inner end of the head portion prevents leaks.

FIG. 11a also illustrates an alternative plug 860 for blocking the flowchannel through the stem section 432 of the handle portion 428. The plug860 is similar to the plug 344, with the exception that the plug issolid and does not incorporate a second sealing flange. The solid plughas greater strength and the elimination of the second sealing flangereduces binding.

To ensure proper operation of the assembly 10, the assembly includes anumber of additional sealing members, which will now be described. Afirst seal or O-ring 252 is mounted at the upper end 44 of theattachment 30 within the inner O-ring seat defined by the first annularlip 76 and overhanging flange 82 out of the coupler 70. The first O-ring252 is secured within the seat by means of an annular retaining clip 254which desirably surrounds the depending ridge 84. Referring to FIGS. 6and 6a, a second seal or O-ring 256 surrounds the second end 114 of theshaft 110 and desirably abuts against the radially outward extendingportion 118 of the shaft 110. To ensure that the piston 130 forms asealing engagement with the internal wall 48 of the body 40 of theattachment 30, the piston 130 is desirably provided with a first and asecond sealing gasket or cup seals, 258 and 260, respectively.Specifically, the body 132 of the piston 130 desirably defines anannular space between the bottom 136 of the piston and the portion ofthe body 132 which defines the outer annular surface 144 and the gaskets258 and 260 are resiliently secured to the body 132 filling the space.The gaskets 258 and 260 ensure that the piston 130 forms a fluid-tightseal with the internal wall 48 of the body 40 and prevent flow betweenthe gaskets 258 and the external wall of the piston body.

FIG. 8 shows an alternative piston design which may be desirable toavoid the need for relatively expensive cup seals. Specifically, thepiston 400 defines an outer generally cylindrical surface 402 which isbisected by an annular triangular groove 404 which receives a sealingmember or O-ring 406. The O-ring 406 ensures a fluid-tight seal betweenthe piston 400 and the internal wall of the body of the attachment.

Referring now to FIGS. 9, 9A and 9B, there is shown a second alternativepiston 450 which may be desirable to avoid the need for separate seals.The piston 450 defines an outer cylindrical surface 452, an upperannular lip 454, and a lower annular lip 456. Advantageously, use ofthis piston 450 avoids the need for a separate O-ring seal and reducesthe stacking of tolerances. Specifically, in designs using separateO-rings, it is required to maintain the tolerance of the inner wall ofthe body, the external cylindrical wall of the piston, and the O-ringitself. By eliminating the use of the separate O-rings, it is onlynecessary to maintain the tolerances of the piston 450 and the innerwall of the body 40.

FIG. 10 shows a third alternative piston design 470. The piston 470defines an outer cylindrical surface 472, an intermediate recess 474, anupper annular foot 476 and a lower annular foot 478. Other than theintermediate recess, the piston 470 is similar to the piston 450. Theintermediate recess 474 has the advantage of providing a piston withuniform wall thickness and a piston which requires less material tomanufacture.

The assembly 10 is desirably provided with a mechanism for locking thehandle in a fully retracted position. Referring to FIGS. 1, 3 and 4, thecoupler 70 desirably defines a pair of parallel L-shaped overhangingflanges 270. The flanges 270 are sized and shaped to permit a lockingplate 272 to slide snugly between the flanges 270. The locking plateincludes a first end 274 and a second end 276. The first end 274 definesa first grip portion 278 and the second end 276 defines a second gripportion 280. Desirably, the locking plate defines a vent passage 282which cooperates with a corresponding vent opening 322 in the base 72 ofthe coupler 70, when the locking plate is in its unlocked position.Surrounding the top of the vent opening 322 is a sealing member 324,such as an O-ring to prevent leakage of fluid when the locking plate 272is in its locked position, as shown in FIG. 1c.

The locking plate 272 defines an aperture 284 including a first smallerportion 286 defined by first edge 288 sized and shaped to snugly receivethe portion of the stem 192 of the handle 190 above the larger mouthportion 202. The aperture 284 further includes a larger second portion290 defined by a second edge 292 which is sized and shaped to permit thefree movement of the larger mouth portion 202 of the stem 192 of thehandle 190 therethrough.

Referring to FIG. 3, the base 72 of the coupler 70 desirably defines araised dimple 325 positioned to abut the outer edge of the locking plate272 to keep the locking plate from sliding when the locking plate 272 isin the open position. Advantageously, the locking plate 272 is providedwith a mating detent 326 to receive and retain the dimple 325 when thelocking plate is in the closed position shown in FIG. 4.

Referring to FIGS. 18-21, a sprayer 500 for use in connection withassembly will now be described in detail.

The sprayer 500 includes a generally cylindrical grip 502, a narrow nose504 having a generally plus-shaped cross-section and a spray end 506.Advantageously, a separate spray piece 508 is provided to permit thespray to be adjusted.

The sprayer 500 includes an actuator 510 surrounded by a thumb rest 512(FIG. 19). As best seen in FIG. 21, the grip 502 of the sprayer 500defines a pair of openings 514. Each opening is defined by a firstgenerally c-shaped wall defining a larger portion of the opening 518 anda second c-shaped wall 520 defining a smaller portion of the opening522.

The grip 502 also defines a slot 530 for receiving the connector 850.The connector 532 is connected by a length of tubing 534 to a valvehousing 550. Advantageously, the tubing 534 is wrapped around a valvehousing to prevent any pulling on the tubing 534 from disconnecting thelink tubing 534 from the valve housing 550.

As best seen in FIGS. 22-23, the valve housing 550 includes an inletportion 552 including a first wall 554 which defines an inlet channel556 and a first port 558. The valve body also includes an outlet portion562 which includes a second wall 564 which defines an outlet channel 566which in turn defines a second port 568. The inlet portion 552 and theoutlet portion 562 are connected by an intermediate portion 572. Theintermediate portion 572 includes a third wall 574 which defines aconnecting chamber 576. The third wall further defines a bottom ventport 578. The inlet portion 552 defines a pocket 582 for receiving alocking ring 584 to secure the tubing 534 within the inlet channel 556.

The actuator 510 is connected to and is integrally formed with thevalve. The valve has a valve shaft 588 including a narrow portion 590. Afirst recess 592 is positioned above the narrow portion 590 and receivesa first O-ring 594. A second recess 596 is positioned below the narrowportion 590 and receives a second O-ring 598. A third recess 600 ispositioned below the second recess and receives a third O-ring 602.

FIG. 22 shows the valve in a off position, with flow entering the inletportion 552 and seeking to flow into the intermediate portion 572through the first port 558. Flow, however, is blocked by the secondO-ring 598 positioned just above the first port 558 and the third O-ring602 positioned just below the first port 558.

FIG. 23 illustrates the valve in a flow through position where the valveshaft 588 has been depressed so that both the second O-ring and thethird O-ring are positioned below the first port 558. As such, flow isable to pass through the first port 558 around the narrow portion 590 ofthe valve shaft 588 through the second port 568 and through the outletportion 562 of the valve housing 550. Advantageously, the lower ventport 578 prevents fluids from being trapped in the valve body, whichotherwise might prevent operation of the valve.

FIG. 24 illustrates a first alternative valve assembly including a valvehousing 610 defining an inlet portion 612 having a first wall 614 whichdefines an inlet channel 616 and a first port 618. The valve housing 610further includes an outlet portion 622 including a second wall 624 whichdefines an outlet channel 626 and a second port 628. The valve housinglikewise includes an intermediate portion 632 between the inlet portion612 and the outlet portion 622. The intermediate portion 632 defines athird wall 634 which defines a connecting chamber 636 and a closed end640. The actuator includes a valve shaft 644 having a narrow portion 646and a first recess 648 for receiving a first O-ring 650. The valve shaft644 likewise defines a second recess 652 for receiving a second O-ring654. FIG. 24 illustrates the valve in a closed position. Flow isprevented from flowing through the assembly by the third wall 634 of theconnecting chamber and the second O-ring 654.

FIGS. 25 and 25A illustrate the valve assembly in an open position, withthe valve depressed. In this position, the valve shaft 644 is depressedso that a portion of the narrow portion 646 of the shaft is aligned withthe first port 618 so that flow through the first port 618 around anarrow portion 646 of the valve shaft 644 and through the second port628 is permitted. Importantly, fluid is not trapped within the closedend 640 of the valve body 610 because the first port 618 is sized,shaped, and positioned such that in the on position, fluid is permittedto flow not only through the inlet portion 612 above the second O-ring654 but also from the closed end 640 of the valve body 610 beneath thesecond O-ring and back into the inlet portion 612 of the valve body.This arrangement prevents fluid from dripping out of the valve body,while at the same time preventing fluid trapped within the closed end ofthe valve body 610 from preventing proper operation of the valve.

FIG. 26 shows a second alternative valve assembly including analternative valve housing 660. The valve housing 660 includes an inletportion 662 having a first wall 664 which defines an inlet channel 666and a first port 668. The valve housing 660 also defines an outletportion 672 having a second wall 674 which defines an outlet channel 676and a second port 678. Positioned between the inlet portion 662 and theoutlet portion 672, is an intermediate portion 682. The intermediateportion 682 has a third wall 684 which includes an upper portion 686 anda lower portion 688. The third wall defines a connecting chamber 690.

The valve shaft 700 includes an outer section 702 connected to theactuator, a narrow intersection 704 and an intermediate section 706. Theouter section 702 has a larger diameter than the intermediate section706 and the intermediate section 706 has a larger diameter than theinner section 704. A first sealing flange 710 is positioned between theouter section 702 and the intermediate section 706 of the valve shaft. Asecond sealing flange 708 is positioned at the distal end of the innersection 704 opposites the outer section 702. Advantageously the firstsealing flange 710 cooperates with the upper portion 686 of the thirdwall 684 to prevent fluid from passing out of the valve body 660.Similarly, the second sealing flange 708 cooperates with the lowerportion 688 of the third wall 684 to prevent fluid from passingtherebetween. FIG. 26 illustrates the second alternative embodiment ofthe valve in a closed position. In this position, flow is permittedthrough the inlet portion 662 and into the connecting chamber 690, butis prevented from flowing through the second port 678 by the secondsealing flange 710. FIG. 27 illustrates the second alternative valve inan open position. In this position, the actuator shaft 700 is depressedand fluid flows through the inlet channel 666 through the first port 668around the inner section 704 of the actuator shaft 700, through thesecond port 678 and through the outlet channel 676.

The operation of the apparatus will now be described.

Referring to FIGS. 1 and 1d, during storage or shipment, the shaft 110is secured in its fully retracted position, with the shoulder or mouthportion 202 of the handle 190 being retained in position by the lockingplate 272. During shipment, the tubing 222 connecting the spray nozzle222 to the handle 190 may be secured in a hollow portion of the spraynozzle 220. The nozzle 220 is desirably provided with a pair of openings340 for receiving and retaining a pair of mating studs 342 projectingfrom the side of the container 20.

FIG. 15 shows an alternative assembly 720 including a container 730, apump attachment 740 and a sprayer 750. The container includes a pair ofstuds 752 positioned on the back wall of the container. Each of studs isidentically shaped. The assembly 720 is generally the same as theassembly 10, with the exception of the shape of the studs. As shown inFIG. 15, the sprayer 750 is mounted on the container 730 by means ofcooperation of the studs 752 and the wall of the sprayer defining thebayonet openings. As best seen in FIGS. 15 and 17, the studs 752 includea stem portion 754 and a taller and wider head portion 756. The headportion defines a first overhang portion 758 which extends beyond theedge of the stem portion 754 a distance D1. Similarly, the head portion756 defines a second overhang 760 extending beyond the opposite side ofthe stem portion 754 a distance D2. Advantageously, the distances D1 andD2 are at least 0.015 inches, and are preferably 0.025 inches.

This mounting arrangement is superior to the mounting arrangements ofprior art in that it facilitates the manufacture of a simple,inexpensive and secure mounting means for the sprayer.

FIGS. 12-14 illustrate a prior art assembly 770 including a container772, connected by tubing 774 to a sprayer 776. The sprayer includes anozzle 778, a trigger 780 and a handle 782. The container 772 defines arecess 784 and a sidewall for receiving the nozzle 778, trigger 780 andhandle 782 of the sprayer 776. The container 772 defines a pair ofgenerally rectangular raised protrusions 786 which extend outward fromthe side wall of the container 772. As best seen in FIG. 14, theprotrusion 786 defines side grooves 788.

The sprayer 776 defines a pair of I-shaped openings 800 corresponding inlocation to the location of the protrusions 786 on the container 772.Each I-shaped opening 800 defines a pair of opposing spring tabs 802. Asdisclosed in U.S. Pat. No. 5,469,993, to Monsanto, the opposing springtabs 802 are to be resiliently received by the side grooves 788 tosecure the sprayer 776 to the container 772 during storage. The '993patent discloses that the container is preferably made by blow molding.As shown in FIG. 14, the protrusions 786 define a first overhang 804extending beyond the inner portion of the recess a distance D3 and asecond overhang 806 extending beyond the outer surface of the recess adistance D4. Unfortunately, this design is undesirable in that it isvery difficult to manufacture the opposing spring tabs 802 of thesprayer 750 and the protrusions 786 of the container 730 to sufficienttolerances that the sprayer can be securely attached to the container730 in this manner. In an effort to avoid having the sprayer detach fromthe container during shipment, sprayers of this design have been gluedto containers or tied to the containers during shipping. Neither ofthese approaches was desirable from an aesthetic, cost or functionalbasis.

Importantly, however, the assembly 720 of the present inventionovercomes these drawbacks. The positioning of the studs 752 along theseam line 812 of the container 730 permits the studs 752 to bemanufactured with a significantly larger first overhand distance D1 andsecond overhang distance D2. As a result, the studs, in cooperation withthe bayonet openings of the sprayer 750, can secure the sprayer 750securely to the container 730 during shipment.

The reason that this larger overhang is possible is best understood inconnection with FIG. 17 which schematically illustrates the method ofmanufacturing a container 730. A first mold half 814 and a second moldhalf 816 are positioned on either side of a break plane 818. Plastic isthen blown into the mold to form the container 730. Because the moldhalves separate in a direction perpendicular to the break plane, thefirst mold half 814 can define a first flange 820 which extends beyondthe side of the stem 754 a distance approximately equal to D1.Similarly, the second mold half 816 can form a second flange 822 whichextends beyond a recess a distance approximately equal to D2.

As shown in FIG. 1d, during shipment the inlet to the internal flowchannel 204 of the stem 192 of the handle is blocked by a plug 344mounted within the internal flow channel 206 of the horizontal portion194 of the handle. The plug 344 includes first and second sealingflanges 346 and 348 which prevent the flow of fluid between them and thewall forming the internal flow channel 206. The end of the plug 344facing the open end 210 of the handle 194 defines a cutout 350.

Importantly, the mating of the upper nipple 162 of the check valve 160with the inlet 124 of the shaft prevents fluid from leaking out thehandle during shipment and storage of the assembly 10, prior to use. Onthe other hand, the plug 344 provides a fail-safe backup in the eventthe locking plate 272 is moved to the open position and the handle israised.

When it is desired to use the assembly 10 to dispense fluid 260 from thecontainer 20, the adaptor 300 on the end of the tubing 222 is insertedinto the internal flow channel 206 of the horizontal 194 portion of thehandle. This causes the inner section 306 of the adaptor 300 to push theplug away from the outlet of the internal flow channel 206 of thehorizontal portion of the handle so that the sealing flanges 346 and 348are pushed beyond the outlet of the internal flow channel 204 of thestem 204, as shown in FIG. 1a. The inner section 306 of the adaptor 300forms a port with the cutout 350 of the plug 344 through which fluid mayflow from the internal flow channel 206 of the horizontal portion 194 ofthe handle 190 and the interior flow channel 309 of the adaptor 300. Thelocking plate 272 is then moved from the locked position shown in FIG. 4to the unlocked position shown in FIG. 3. The grip portion 194 of thehandle can then be lifted upward as illustrated in FIG. 2. This causesthe second O-ring 256 to press against the tapering portion 142 of thebody 132 of the piston 130 creating a fluid-tight seal. This also causesthe fluid 260 to be drawn through the check valve 160 into the lowerportion 152 of the chamber 42. It is not necessary to draw the handlecompletely upward. On the other hand, to maximize the amount of fluidthat may be dispensed without repressurizing the container, the handlemay be drawn to its fully pressurized position as illustrated in FIG. 5.In this position, the spring 180 is fully compressed between the coupler70 and the piston 130. The handle 190 is then released, allowing thespring 180 to force the piston 130 downward against the fluid 260 in thelower portion 152 of the chamber 42. As the check valve 160 preventsfluid from flowing out of the chamber 42 fluid is forced upward throughthe inlet end 124 of the internal flow channel 122 defined by the shaft110. This fluid flows through the internal flow channel 200 of the stem192 and the internal flow channel 206 of the grip portion 194 of thehandle 190. The fluid is likewise forced through the tubing 222 to thespray nozzle 220. Fluid is dispensed from the spray nozzle 220 bydepressing the actuator 240 operating the release valve (not shown) forthe nozzle 220.

Significantly, the assembly 10 of the present invention permits thequick and easy release of pressure within the pump attachment 30.Specifically, as shown in FIGS. 6 and 6a, the handle 190 can be forcedrapidly downward so as to move the second end 114 of the shaft 110downward relative the piston 130. This causes the second O-ring mountedon the radially outward extending portion 118 of the lower end 114 ofthe shaft 110 to move downward away from the tapering portion 142 of theinner annular surface 138. This releases a seal between the shaft 110and the piston 130 and permits fluid 260 to flow through the channel 140between the inner annular surface 138 of the piston 130 and the outersurface of the shaft 110. This fluid 260 is eventually drained from theupper portion 150 of the body 40 of the attachment through a pair ofoutlet openings 346.

Importantly, the release of pressure from the body 40 of the attachment30 prevents fluid from inadvertently being released from the assembly 10during operation, transport and storage of the apparatus. Further, asillustrated in FIG. 7, this release of pressure permits the shaft 110 toreturn to its fully retracted position so that the mouth portion 202 ofthe handle can be received within the aperture 74 in the coupler 70against the coupler 70 and locked in place against the handle seat bythe locking plate of the coupler.

Those of skill in the art will recognize that this invention may beembodied in several forms, without departing from the spirit of theinvention, and the foregoing description is therefore intended to beillustrative and not restrictive.

We claim:
 1. A pump attachment for a container defining a neck,comprising: a body defining an elongate chamber having a first end, asecond end and an interior wall extending between said first end andsaid second end; a coupler sized and shaped to secure said body to aneck of a container; a shaft extending through an opening in said firstend of said chamber, said shaft defining an internal flow channel; aone-piece piston reciprocally mounted within said chamber, said pistondefining an inner annular surface surrounding said shaft and an upperouter annular surface sized and shaped to form a sealing engagement withsaid interior wall of said body and a lower outer annular surface sizedand shaped to form a sealing engagement with said interior wall of saidbody, said piston separating said chamber into an upper portion abovesaid piston and a lower portion below said piston; an inlet valve atsaid second end of said body, configured to permit the flow of fluidinto said chamber and restrict the flow of fluid out of said chamber;and a biasing member between said piston and said first end of saidchamber, wherein said attachment further defines a first sealing surfacesubstantially fixed with respect to said piston and a second sealingsurface substantially fixed with respect to said shaft, said firstsealing surface and said second sealing surface having a first positionwherein said first sealing surface and said second sealing surfacecooperate to prevent the flow of liquid between said piston and saidshaft and a second position wherein said first sealing surface and saidsecond sealing surface permit the flow of liquid between said piston andsaid shaft.
 2. The attachment of claim 1, wherein said upper outerannular surface is defined by an upper lip adapted to flex outward inresponse to downward pressure and said lower outer annular surface isdefined by a lower lip adapted to flex outward in response to upwardpressure.
 3. The attachment of claim 2, wherein said piston furthercomprises an inwardly tapered seat, which defines said first sealingsurface.
 4. The attachment of claim 3, wherein said attachment furthercomprises an O-ring mounted on said shaft, which defines said secondsealing surface.
 5. The attachment of claim 1, wherein said attachmentfurther comprises a spray nozzle communicating with said internal flowchannel.
 6. The attachment of claim 5, wherein said attachment furthercomprises an actuator for selectively preventing the flow of fluidthrough said spray nozzle.
 7. The attachment of claim 1, wherein saidattachment further comprises a handle secured to said shaft.
 8. Theattachment of claim 7, wherein said attachment further comprises a latchmovable between a first location wherein said latch generally preventssaid shaft from being drawn through said first end of said body and asecond location wherein said latch generally permits said shaft frombeing drawn through said first end of said body.
 9. The attachment ofclaim 8, wherein said attachment further comprises a spray nozzlecommunicating with said internal flow channel.
 10. A pump attachment fora container defining a neck, comprising: a body defining an elongatechamber having a first end, a second end and an interior wall extendingbetween said first end and said second end; a coupler sized and shapedto secure said body to a neck of a container; a shaft extending throughan opening in said first end of said chamber, said shaft defining aninternal flow channel; a handle integrally formed with said shaft so asto form a single piece; a piston reciprocally mounted within saidchamber, said piston defining an inner annular surface surrounding saidshaft and an outer annular surface sized and shaped to form a sealingengagement with said interior wall of said body, said piston separatingsaid chamber into an upper portion above said piston and a lower portionbelow said piston; an inlet valve at said second end of said body,configured to permit the flow of fluid into said chamber and restrictthe flow of fluid out of said chamber; and a biasing member between saidpiston and said first end of said chamber, wherein said attachmentfurther defines a first sealing surface substantially fixed with respectto said piston and a second sealing surface substantially fixed withrespect to said shaft, said first sealing surface and said secondsealing surface having a first position wherein said first sealingsurface and said second sealing surface cooperate to prevent the flow ofliquid between said piston and said shaft and a second position whereinsaid first sealing surface and said second sealing surface permit theflow of liquid between said piston and said shaft.